[Haskell-beginners] Counting Fruits

Adolfo Builes builes.adolfo at googlemail.com
Thu Feb 19 18:15:33 EST 2009

Hello everyone ,
I wanted to do a small program which read a txt with fruit's name in each
line and then print how many fruits I have of each type. something like

and then


I came up whit this

import qualified Data.Map as Map
import Data.List
import System.IO

main =
      file <- readFile "fruits.txt"
      let answer = proccessFile $ lines file

      putStrLn (show answer)

proccessFile :: [String] -> [(String,Int)]
proccessFile file = Map.toAscList $ parseFile Map.empty  file
    where parseFile fruits [] = fruits
          parseFile fruits_map (x:xs) = parseFile (Map.insertWith (+)
x 1 fruits_map) xs

It works, but I would like to know how would  you do it ?,  Share different
points of view, different code. Was it a good idea to use a Map  ?, Did I
separate the code  in a proper way, I mean pure - impure ? How can we
improve the performance ?

Best Regards for everyone.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.haskell.org/pipermail/beginners/attachments/20090219/1162574a/attachment.htm

More information about the Beginners mailing list